Nucleic Acids (CH 3.3) Flashcards
What does the Biochemical activity of the cell depend on?
-Production of a large number of proteins that each have their own specific sequence
What are the 2 main varieties of Nucleic Acid?
- Deoxyribonucleic Acid (DNA)
- Ribonucleic Acid (RNA)
What is the difference between the roles of DNA & RNA?
- Genetic info is stored in DNA
- RNA= copies of genetic info that is then used to direct the synthesis of proteins during gene expression
What is the defining characteristic of Nucleic Acids?
-They’re able to serve as templates for producing precise copies of themselves= allows genetic info to be PRESERVED during cell division & reproduction of organisms
What is the role of RNA?
- Carries info
- Part of the organelle responsible for protein synthesis
- Involved in the control of gene expression
What is Messenger RNA?
- AKA mRNA
- Consists of transcribed, single-stranded copies of portions of the DNA
- The transcripts that mRNA carries are the blueprints that specify the amino acid sequences of proteins
What are Nucleic Acids made of?
- Long polymers of repeating subunits= nucleotides
- SO BASICALLY a Chain of 5 carbon sugars linked together by phosphodiester bonds with a nitrogenous base protruding from each sugar
What are the 3 basic components for the structure of a Nucleotide?
- 5 carbon sugar/ Pentose if you wanna get fancy. The sugar would be RIBOSE in RNA & DEOXYRIBOSE in DNA
- A phosphate group (polar & negatively charged)
- Organic nitrogenous base (C,H,N,O but mostly nonpolar)
What are Polynucleotides?
-Chains of Nucleotides
-Have polarity= A phosphate on the top end and an OH sugar at the bottom end
-Phosphate end being 5’ & the -OH sugar being 3’
(5’ would be at the top)
What are the 5 different types of Nitrogenous Bases?
- Adenine
- Cytosine
- Guanine
- Thymine (DNA ONLY)
- Uracil (RNA ONLY)
What are the Purines?
- Large, Double ringed molecules found in BOTH DNA & RNA
- Purines= Adenine & Guanine
What are Pyrimadines?
- Small, Single ringed molecules
- Cytosine (BOTH DNA & RNA)
- Thymine (DNA ONLY)
- Uracil (RNA ONLY)
What do organisms use the sequences of Nucleotides in DNA for?
-To encode the information specifying the amino acid sequences of their proteins
How do DNA molecules look like in Eukaryotes?
-2 chains wrapped around eachother in a LONG LINEAR MOLECULE= double helix double stranded
How do DNA molecules look like in Prokaryotes?
-Circular moleule
How are the 2 strands of DNA connected?
- By base-pair
- The pair consists of a base in one chain attracted by hydrogen bonds of the base pair of the other chain (hydrogenous bonds between nitrogenous bases)
What bases pair together?
- Adenine pairs w/ Thymine in DNA or Uracil in RNA
- Cytosine pairs w/ Guanine in DNA & RNA
How is RNA different from DNA structurally?
- Designates Ribose as the sugar in it’s sugar-phosphate back bone
- RNA molecules use Uracil amoung its nitrogenous bases (one of its carbons lacks a -CH3 group)
How does RNA look like?
-Single stranded
What are the different roles of RNA?
- Can carry info= mRNA
- Part of the ribosome= rRNA
- Carries amino acids= tRNA
What is the structure of DNA?
- Double stranded, double helix
- Designates Deoxyribose as the sugar in the sugar-phosphate backbone
- Uses Thymine alone its nitrogenous bases
What are the 3 most important Nucleotide-containing molecules?
- Adenosine Triphosphate= energy currency for the cell
- Nicotinamide Adenine Dinucleotide (NAD+)
- Flavin Adenine Dinucleotide (FAD)
- Both NAD+ & FAD function as electron carriers in a variety of cellular processes
How many bonds are between A & T?
-2 H bonds
How many bonds are between C & G?
-3 H bonds
How would you tell if a Nucleotide is DNA or RNA?
- Depends on the R group (2’) of the sugar
- If its -OH then its RNA
- If it’s -H then its DNA
How do Nucleic acids polymerize?
- By using the sugar & phosphates group of a nucleotide
- When the phosphate & sugar groups polymerize, they make the BACKBONE of the Nucleic acid molecule= Phosphate backbone
What is removed to allow Nucleic acids to polymerize & why?
- H from sugar & an OH from phosphate are removed during synthesis
- When these atoms are removed, the bonds between these two groups= Phosphodiester bonds
What are the bases attached to in order to stay put in the Nucleic Acid molecule?
-The bases are covalently attached to ribose sugar & that is attached to the phosphate backbone
What do the sequence of Bases along w/ the polymer determine?
- Important basis for heredity
- The sequence is written as 5’-3’ bc the opposite direction would have completely different info
- RNA & DNA sequences & their changes are behind evolution & diversity
What are are the 4 important polymers?
- Polypeptides/ proteins
- Nucleic Acid (DNA/RNA)
- Complex Carbohydrates
- Tryglycerides & phospholipids
What are the 4 important monomers?
- Amino Acids
- Nucleotides
- Simple Sugars
- Fatty acids/ glycerol/ phosphate
What are the monomers that make up Polypeptides/Proteins?
-Amino acids
What are the monomers that make up Nucleic Acid?
-Nucleotides
What are the monomers that make up complex carbs?
-Simple Sugars
What are the monomers that make up Triglyceride/phospholipids?
-Fatty acids, Glycerol, Phosphate
